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Exploitation and protection of water resources
Based on UN recommendation, the daily amount of safe freshwater per person is 20 – 50 litres. Nevertheless, almost 900 millions of people worldwide have no access to such amount of safe freshwater.
The total volume of water on Earth is approximately 1.4 billion km3. The volume of freshwater reaches 35 millions km3, which represents only 2.5 % of the total water amount, the remaining 97.5 % are formed by saltwater in oceans and seas. 70 % of freshwater occur in the form of glaciers and snow cover. The remaining 30 % of freshwater occur in the form of groundwater and soil water. Lake water and river water represent only 0.3 % of the total freshwater volume. Of the mentioned amount, less than 1 % only is exploitable for ecosystems and mankind.
World population of 6 billion people exploit 54 % of available water in lakes, rivers and groundwater. 70 % of water are used for irrigation, 22 % for industry and 8 % for domestic consumption. Daily consumption of drinking water per person is 2 – 4 litres, but, 2000 – 5000 litres of water are needed to produce a daily food consumption per person.
Although one of the millenium development goals is to reduce by 2015 the number of people lacking quality access to safe drinking water and basic hygiene, it is evident that safe drinking water supply for the population will remain in the future a big problem which will have to be tackled especially by developing countries, mainly by out-of-the-way rural communities which are often off interest to large development as well as commercial projects.
The term sustainable technologies in water management means not only exploitation of renewable energy sources for water abstraction, but primarily such water management, where irreversible negative impacts on water balance in the area concerned are avoided and principles of water protection against pollution are consistently followed. And not only this – sustainable water management and appropriate technological processes may even significantly improve often deteriorated ecological balance of rural areas.